1. Field of the Invention
The present invention relates to a pair of shears and, more particularly, to a pair of gardening shears.
2. Description of the Related Art
A pair of conventional gardening shears in accordance with the prior art shown in FIGS. 10 and 11 comprises a handle (not shown) having a lower end provided with a pivot head 42, a drive member 47 mounted in the handle, a control lever (not shown) pivotally mounted on an upper end of the handle and connected to an upper end of the drive member 47 to drive the drive member 47, a transmission device 40 mounted on the pivot head 42 of the handle and connected to a lower end of the drive member 47, and two cutting blades 41 pivotally mounted on the transmission device 40 and driven by the drive member 47 via the transmission device 40.
The transmission device 40 includes a housing 48 on which the pivot head 42 of the handle is pivotally mounted, a pivot plate 46 mounted in the housing 48 and having a first end pivotally mounted on the lower end of the drive member 47 to move therewith, a connecting plate 45 having a first end pivotally mounted on a second end of the pivot plate 46 to move therewith, a link 43 movably mounted in the housing 48 and having a first end pivotally mounted on a second end of the connecting plate 45 to move therewith and a second end protruded outwardly from the housing 48 and pivotally mounted on one of the cutting blades 41 to open or close the cutting blades 41, and a restoring member 44 mounted in the housing 48 and biased between the link 43 and the housing 48. The second end of the pivot plate 46 is formed with a guide slot 461, and the first end of the connecting plate 45 is slidable in the guide slot 461 of the pivot plate 46.
In operation, when the control lever is pressed, the drive member 47 is pulled upward to pull the pivot plate 46 and the connecting plate 45 to pull the link 43 backward to move one of the cutting blades 41 so as to close the cutting blades 41. At this time, the restoring member 44 is pulled and compressed by the backward movement of the link 43 to store a restoring force. After the force applied on the control lever is removed, the link 43 is moved forward by the restoring force of the restoring member 44 to return to the original state to move one of the cutting blades 41 so as to open the cutting blades 41 again.
However, the restoring member 44 is pulled and compressed by the link 43, so that the restoring member 44 is subjected to a pulling force constantly and is easily worn out by the pulling force during a long-term utilization, thereby decreasing the lifetime of the restoring member 44. In addition, when the pivot head 42 of the handle is rotatable relative to the housing 48, the pivot plate 46 touches and directly rubs the inner wall of the pivot head 42, so that the pivot plate 46 is easily worn out by the friction during a long-term utilization, thereby decreasing the lifetime of the pivot plate 46.